Compline

The name, Compline, is due to St Benedict, although the liturgy itself preceded him. It is of later origin than Vespers and began as monastic night prayer. St Benedict, in his Rule, gave it the form most commonly used. The Church later added to the non-monastic form the Nunc dimittis. Historically, the popular usage of the traditional Compline hymn, Lucis Ante Terminum ('To Thee before the close of day'), suggests that some light still remained when Compline was said. 

THE CANTICLE OF SIMEON: THE NUNC DIMITIS

A chief fixed canticle  the Compline liturgy is the Canticle of Simeon, from St. Luke's Gospel.

The Canticle of Simeon (St. Luke 2:29-32) is known as the Nunc dimittis, from the first two words of the Latin translation of text (meaning “Now you dismiss”). It combines the quiet, intimate confidence of a humble and faithful servant of God with a bold and comprehensive summary of God’s purposes for all the world and for all of history. A final Gloria Patri, which is traditionally added):

Nunc dimittis servum tuum, Domine, secundum verbum tuum in pace:
Lord, now lettest thou thy servant depart in peace according to thy word.

Quia viderunt oculi mei salutare tuum
For mine eyes have seen thy salvation,

Quod parasti ante faciem omnium populorum:
which thou hast prepared before the face of all people;

Lumen ad revelationem gentium, et gloriam plebis tuae Israel.
To be a light to lighten the Gentiles and to be the glory of thy people Israel.

Gloria Patri, et Filio, et Spiritui Sancto:
Glory be to the Father, and to the Son: and to the Holy Ghost;

Sicut erat in principio, et nunc, et semper, et in sæcula sæculorum. Amen.
As it was in the beginning, is now, and ever shall be: world without end. Amen.

The traditional Marian antiphon sung after the Compline (Night Prayer) varies by the liturgical season: the Alma Redemptoris Mater for Advent and Christmas, the Ave Regina Caelorum for Lent, the Regina Caeli for the Easter season, and the Salve Regina for the rest of the year. These four seasonal antiphons honor the Blessed Virgin Mary and conclude the daily Divine Office, leaving the faithful with her words and imagery as they turn to rest.  

Here is a breakdown of the traditional schedule: 

• Alma Redemptoris Mater: (Loving Mother of our Savior): From the start of Advent until February 2nd, the Feast of the Presentation.

• Ave Regina Caelorum: (Hail, Queen of Heaven): From February 2nd (or slightly later if the 2nd is not on a Sunday) until Holy Week.

• Regina Caeli: (Queen of Heaven): From Easter Sunday until Pentecost.

• Salve Regina: (Hail, Holy Queen): From Pentecost until the start of Advent